Model of the subunit architecture of eukaryotic vacuolar ATPase.

2012-10-12T02:41:03Z (GMT) by Lee S. Parsons Stephan Wilkens
<p>(A) V<sub>1</sub>-ATPase (top) and membrane bound V<sub>o</sub> proton channel (bottom) are linked by three peripheral stalks (EG1, EG2, EG3) that connect the top of the V<sub>1</sub> to subunits C, H, and the N-terminal domain of the membrane integral subunit <i>a</i> (<i>a</i><sub>NT</sub>). Subunits C, H and <i>a</i><sub>NT</sub> are two domain proteins with C<sub>head</sub> and C<sub>foot</sub>, H<sub>NT</sub> and H<sub>CT</sub>, <i>a</i><sub>NT</sub>(proximal) and <i>a</i><sub>NT</sub>(distal) domains, respectively. (B) During enzyme regulation by reversible dissociation, V<sub>1</sub>-ATPase is released from the membrane bound V<sub>o</sub> and the activity of both resulting complexes is silenced. To enable enzyme disassembly, protein-protein interactions involving subunits EG, C, H, DF, <i>d</i> and <i>a</i><sub>NT</sub> have to be broken.</p>